Axial, triple-separation, diffusion apparatus and method

ABSTRACT

A reservoir containing an essential oil feeds to an eductor injecting a jet forming a plume of air entraining oil droplets. A series of drift chambers act as velocity reducers to alternately slow the flow droplets with entry, and then reaccelerate them upon exit through an exit channel. A micro cyclone separator operates between at least two of the drift chambers, exposing the flow to circumferential direction and centripetal acceleration driving comparatively larger droplets out of the flow away from comparatively finer droplets sufficiently small to remain with the flow of air. Separation of comparatively larger droplets, effectively eliminates “spitting” of liquids that might or rapid drift onto surrounding surfaces.

RELATED APPLICATIONS

This application: is a divisional of U.S. patent application Ser. No.14/850,789, filed Sep. 10, 2015; which is a continuation in part of U.S.patent application Ser. No. 13/854,545, filed on Apr. 1, 2013, issued asU.S. Pat. No. 9,415,130 on Aug. 16, 2016; both of which are herebyincorporated by reference in their entirety.

BACKGROUND

Field of the Invention

This invention relates to use of essential oils and, more particularly,to novel systems and methods for diffusers distributing atomized andvaporized essential oils from a reservoir.

Background Art

Mechanisms exist for altering a closed environment such as a room orhome with humidity. Likewise, mechanisms exist for removing humidity.Electronic and chemical mechanisms for destroying microbial sources ofscents exist. Meanwhile, sprays, evaporators, wicks, candles, and soforth also exist to distribute volatile scents, essential oils, liquidsbearing scents, and so forth. These may be introduced into breathingair, an atmosphere of room, or any other enclosed space.

Heating often destroys or at least changes the constitution of essentialoils. Thus, it has limitations. However, the evaporation rates oratomization rates of essential oils are often insufficient to provide acontrollable, sustainable, and sufficient amount of an essential oilinto the atmosphere. Thus, wicks having no air movement mechanism oftenprove inadequate.

Meanwhile, mechanisms that seek to copy vaporizers and moistureatomizers often damage surrounding equipment, furniture, and otherenvirons of a space being treated by essential oils. Moreover, thecontinuing “spitting” by atomizers of comparatively larger droplets notonly causes damage to finishes on surrounding surfaces, but wastes asubstantial fraction of the essential oil.

Essential oils are concentrated sources of aromas or scents. Theirextraction from source plants is sometimes complicated, and alwayscomparatively expensive, based on the cost per unit volume of theessential oil. Therefore, colognes, other fragrancing systems, and thelike often use high rates of diluents for essential oils. They also usesynthetic oils and artificial scents that may not replicate thecomforting, familiar, and natural essence of essential oils.

By whatever mode, systems to distribute essential oils often waste anexpensive commodity while damaging surroundings about their atomizers orother distribution systems. Thus, it would be an advance in the art toprovide an apparatus and method for distributing essential oils in assmall particles as possible, preferably vaporized, while protectingsurrounding areas. It would be an advance to do so while retrieving andrecycling for re-atomization or diffusion any droplets that are largerthan those that may be sustained by effectively Brownian motion oncedischarged into surrounding air.

BRIEF SUMMARY OF THE INVENTION

In view of the foregoing, in accordance with the invention as embodiedand broadly described herein, a method and apparatus are disclosed inone embodiment of the present invention as including a reservoir fittedwith an extraction system for drawing out of the reservoir and feedinginto a diffuser nozzle. The nozzle may operate as an eductor. In fact,in certain embodiments an eductor may include an injection nozzlefeeding into a plenum which plenum feeds through a diffuser nozzletoward an ultimate discharge point or port.

In certain embodiments, a system may include separation or driftchambers. For example, an initial separation chamber may actually be anevacuated space or vapor space near the top of a reservoir. Thisprovides the advantage of the reservoir directly relying on contactaccumulation, coalescence by contact between an atomized spray and thecontent of essential oil in the reservoir.

Typically, a sealed or flow-controlling cap may serve as a separatorbetween this initial separation (drift) chamber, and other “downstream”separation (drift) chambers between the initial separation (drift)chamber and the ultimate discharge port. In various embodiments, changesof direction may serve as separation mechanisms. Thus, for example, theatomized flow composed of atomized essential oil and entraining air (airentraining those droplets and carrying them therewith) may pass as anatomized flow or simply flow through a circuitous route.

Changes in direction may be relied upon to coalesce out large dropletsas they impact against striking surfaces. Striking surfaces may benaturally occurring walls of conduits, the reservoir, and so forth.However, striking surfaces may also be made up of baffles simply placedwithin a conduit or path in order to cause changes of direction, and toreceive and coalesce overly large droplets. “Larger” means having toomuch mass, or rather too great a mass-to-surface-area ratio to driftindefinitely in air. This may also be expressed as avolume-to-surface-area ratio.

For example, a sphere has a volume. That volume is related to a thirdpower of radius of the sphere. Thus, four thirds it multiplied by theradius to the third power equals the volume of a sphere having a radiusof r. Meanwhile, the area of cross section (which controls air drag) isrelated to a second power or square of the radius. Surface area of thesphere is also related to the square of the radius. Thus, one can seethat cross sectional area and surface area increase as the square ofradius. Volume (proportional to mass and gravity force) increases as thecube. This means that as radius increases, mass (and gravity force)increases at a greater rate than area (proportional to drag) increases.

Conversely, this means that the decrease of radius decreases surfacearea as the square of radius, while decreasing volume as the cube ofradius. Accordingly, there comes a point at which the cross sectionalarea controlling fluid drag of droplets in air is sufficiently large yetthe mass and volume are sufficiently small, that a particle of such sizemay remain suspended indefinitely in air. That is, the drag forcesresisting drift of the droplet downward with the force of gravity issufficient to maintain indefinitely the drift of that droplet with themovement of air. Stated another way, the gravitational force is sominiscule as to be irrelevant to the time of drift. Gravity isunimportant. Drift can proceed effectively indefinitely.

Evaporation is an entirely different mechanism. In evaporation,individual molecules of a liquid become individual molecules of vapor.Vapors then abide by Dalton's law of partial pressures and take theirplace with other surrounding vapors including air, constituted primarilyby oxygen and nitrogen. Thus, evaporated portions of an essential oilhave performed well their function of distributing into the surroundingair.

Meanwhile, droplets sufficiently small to remain airborne substantiallyindefinitely, despite gravity, have also achieved their mission todistribute in air. Droplets too large, and therefore, too heavy, cannotbe sustained in surrounding air against drift downward under the forceof gravity. By drifting down these become the culprits in waste ofessential oils and the damage to surrounding surfaces on which dropletsland.

Thus, in an apparatus and method in accordance with the invention, ithas been found that multiple separation (drift) chambers have proveneffective to provide several key factors. For example, separationchambers provide time. The time of passage or containment of a dropletwithin a separation chamber provides opportunity for comparativelylarger droplets to drift toward any coalescing surface. By coalescingsurface is meant a surface upon which overly large droplets may strike,and coalesce with one another under the natural surface tension affinitythat the essential oil has for itself.

Also, the separation chambers should provide inlets and outlets offsetfrom one another. Inlets and outlets offset from one another offerchanges of direction. Moreover, changes of direction imply barriers thatwill intercept overly large or “comparatively large” particles byserving as coalescing surfaces. Barriers may also redirect flows,thereby encouraging striking thereof by overly large particles.

Herein we will define overly large particles as particles that arelarger, especially more than an order of magnitude larger in diameterthan self-sustaining (permanently drifting) droplets. Thus, permanentlydrifting droplets are defined as droplets of an atomized liquid that aresufficiently small that they will not drift downward, especially theheight of a room within a day of eight to twenty four hours. Thus, thefinest particles, defined as permanently drifting particles are thosewhose gravitational acceleration under the force of gravity isinsufficient to drift them down. Of interest also is any droplet thatwill not descend the height of a room within a day due to the resistanceto drifting down by the fluid drag of the surrounding gases, such asroom air. As a practical matter, droplets larger than these finest orpermanently drifting particles are sufficiently small if they will driftwith an airflow and leave with ventilation air. Often, air leaves a roomin a matter of less than an hour.

For example, the American Society of Heating, Refrigerating, and AirConditioning Engineering (ASHRAE) defines standards for roomventilation. Finest particles will necessarily be drifting with the flowof air and will leave a room before they have substantial opportunity todrift to the floor. Moreover, because room air is exchanged sofrequently, typically more than once per hour, particles that are anorder of magnitude larger than the finest particles also fit within thedefinition of comparatively smaller particles. In other words, thesestay aloft for sufficient time to be swept out with the circulation ofroom air.

What is therefore needed to be controlled is the comparatively largerparticles those that can drift to the ground in less than an hour orless than an air exchange time. The size may vary with temperature andwith the specific gravity (density compared to the density of water) ofa particular essential oil.

Thus, an apparatus and method in accordance with the invention may relyon a series of separation chambers. These may alternatively be referredto as drift chambers. These provide drift time for comparatively largerparticles to drift toward and coalesce against striking surfaces.

In one embodiment, a parallel eductor, which is effectively a coaxialeductor, operates to inject or atomize a plume of educted gas or vapor(e.g., air) starting as a jet entraining therewith a certain amount ofan essential oil to be atomized. This jet, proceeding out of the jetnozzle or injection nozzle (which initiates and creates the jet), passesthrough a receptacle or well. The well is drawing the essential oil outof the reservoir, through a tube into that receptacle.

The jet of air passing through the essential oil entrains a certainportion thereof, or entrains an essential oil at a rate and withsufficient energy to strip droplets from the surface of surroundingessential oil. It ejects those droplets with the jet through a diffusernozzle.

Of course, according to the laws of physics and engineering, dropletsare generated in a variety of sizes. Initially, the largest of thecomparatively larger droplets will not be able to make the turn requiredto reverse direction. Reversal is required in order to pass back outthrough the cap and a channel in the cap that exits the vapor spaceabove the reservoir.

In some respects the expression “co-axial” is not accurate. It refers tothe fact that several elements literally share a central axis. Here,co-axial refers to the fact that a central axis passes through areservoir and several separation chambers or drift chambers, and othercomponents. However, they need not be symmetric, nor literally co-axial,but their flows' net directions are along a parallel, almost co-axialpath. Meanwhile, the actual injection may be co-axial with the well andeductor nozzle, or may be parallel to the co-axial or central axis. Incertain illustrated embodiments, the injection is nearly co-axial, butactually parallel.

The effect of this parallel or quasi co-axial injection is that thefirst coalescing surface that the comparatively larger droplets strikeis not a surface of a solid at all. It is the upper surface of thesupply of essential oil restored in the reservoir. This provides highlyeffective coalescence. It results in a comparatively large ongoingmomentum transfer from comparatively larger droplets into the uppersurface of the essential oil in the reservoir.

Effectively, this may also entrain air into the upper surface, causing acertain amount of bubbling or foaming at the upper surface of theessential oil in the reservoir.

Conservation of mass principles at work require that the air used forthe jet in the eductor pass out of the vapor space in the reservoir. Atleast one channel is provided for that purpose. Meanwhile, there mayexist a random action or trajectory of an overly large droplet towardany of the walls of the reservoir. Above the line or surface of thecontained essential oil, this may result in those walls becomingcoalescing surfaces. After coalescing overly large droplets, the wallscontinue draining them back into the essential oil contained in thereservoir.

The full change of direction, about 180 degrees, from the injectiondirection toward the surface of the essential oil to the pathway outthrough the exit channel, represents a first separation process. It is adirect-contact coalescence process. Droplets have direct contact withthe content of the reservoir rather than coalescing with one another aseach is smeared by impact against a coalescing surface.

Applicant hereby incorporates by reference: U.S. patent application Ser.No. 12/247,755, filed Oct. 8, 2008, issued Feb. 1, 2011, as U.S. Pat.No. 7,878,418, U.S. Design patent application Ser. No. 29/401,480, filedSep. 12, 2011, issued May 29, 2012, as U.S. Design Pat. No. D660,951;U.S. Design patent application Ser. No. 29/401,517, filed Sep. 12, 2011,issued Sep. 4, 2012, as U.S. Design Pat. No. D666,706; U.S. patentapplication Ser. No. 13/854,545, filed Apr. 1, 2013; U.S. patentapplication Ser. No. 14/260,520, filed Apr. 24, 2014; U.S. Design patentapplication Ser. No. 29/451,750, filed Apr. 8, 2013, U.S. Design patentapplication Ser. No. 29/465,421, filed Aug. 28,213; and U.S. Designpatent application Ser. No. 29/465,424, filed Aug. 28, 2013.

Each of these references, incorporated by reference herein in itsentirety, discloses certain structures, components, controls, operatingmechanisms, and designs for eduction and separation. In thisapplication, Applicant need not, indeed cannot, reiterate all of thedisclosure and illustrations contained therein. However, thosereferences discuss various sizes and shapes of reservoirs, various typesof caps and seals, various separation chambers, various strikingsurfaces or coalescing surfaces, and various paths and separationchambers. Those words are not necessarily used. Therefore, Applicantwill hereby seek to define what is meant by these terms.

By a reservoir is indicated a supply, or a container for holding asupply, of an aromatic substance, such as an essential oil. By adiffuser is meant a system for atomizing and distributed comparativelysmaller particles, including finest particles as defined hereinabove,and suitably fine particles that are within about an order of magnitudeof the same diameter or radius as finest particles.

A jet is defined as in engineering fluid mechanics. A jet represents aflow of fluid having momentum, and passing through another fluid whichmay have the same or a different constitution. Thus, an air jet may passthrough a surrounding oil. An air jet may pass through surrounding air.A significant feature of a jet is that it passes fluid having momentumthrough another fluid having a different specific momentum. Accordingly,momentum is exchanged between the environment and the jet, causing thejet to grow in size as a “plume.” A plume will decrease in velocity asthe momentum is distributed among more actual material (mass).

An eductor is a specific type of fluid handling mechanism. An eductor isa system in which a jet of a first constitution is injected into anotherfluid, typically of a different constitution. The momentum from thefirst jet is sufficient to cause the surrounding fluid entrained by thejet to continue as a plume of mixed constitution.

Herein, an eductor mechanism is created in which a jet, the source ofthat jet, and the surrounding environment into which the jet is injectedare passed through an aperture. Any portion of the jet that exceeds thediameter or maximum dimension across the nozzle cannot passtherethrough, and thereby must recirculate back to be re-entrained inthe jet, or to some other disposition.

A diffuser is in some respects an atomizer, but has the specificobjective of producing finest fluid particles or droplets. Accordingly,a diffuser system includes not just an eductor but separation chambers,sometimes distinct separator structures. All are calculated to removecomparatively larger droplets, leaving only finest droplets and thosewithin an about an order of magnitude thereof. Again, finest droplets orparticles and comparatively larger particles have been definedhereinabove, in terms of their fluid dynamic behaviors. Those behaviorsare defined by well established engineering equations. Therefore, allthose equations are not repeated here. One may refer to textbooks andpapers published on jets, atomization, fluid mechanics, two-phase flow,entrainment, plumes, and the like to obtain the details of the physics,the flow fields, the operational parameters, and governing equations forthese phenomena.

Vapor space in a reservoir is defined as a portion of the volume of areservoir container that contains other than predominantly the liquidfor which the reservoir exists. That is, the vapor region actuallycontains air, a certain amount of the evaporated essential oil,according to Dalton's law of partial pressure in chemistry, and acertain quantity of drifting droplets in transit.

In certain embodiments of an apparatus and method in accordance with theinvention, a reservoir may be fitted with an eductor injecting, througha diffuser nozzle, an entrainment jet containing both air, as thedriving fluid, and atomized particles or droplets of the essential oil.An exit channel discharges some portion of the resulting flow from thevapor space out into a first drift chamber.

In one currently contemplated embodiment, all the drift chambers areeffectively coaxial. The first drift chamber is the vapor space itself.Following passage through the exit channel from the vapor space, asecond drift chamber provides time and a change of direction. It willpermit the comparatively larger droplets to drift to a striking surface,coalesce thereagainst, and flow back toward the reservoir.

In certain embodiments, multiple channels connect drift chambers. Somemay favor passage or exit of the entrainment air. Others may favorreturn of coalesced essential oil back toward the reservoir. Some may beshaped, bordered, leveed, or otherwise configured to favor, others torestrict, the flow of oil back toward the reservoir or to favor the flowof entrained droplets in air toward the discharge port. In certainembodiments, the drift chambers may include baffles, changes ofdirection, circuitous pathways, and the like. Various embodiments ofthese structures are illustrated in the documentation incorporatedherein by reference.

By drift chamber is meant a region of space in which the effective crosssectional area of flow is increased above that immediately precedingentry into the drift chamber. Typically, this change in area may bedouble or more. However, the effective benefit of a drift chamber is aslowing of the air flow.

Mass flow rate is equal an area times the velocity passing through thatcross sectional area, multiplied by a density of the material flowing.Volumetric flow rate is simply a velocity of the flow rate multiplied bythe cross sectional area through which that flow passes.

Whether looking at mass flow rate or volumetric flow rate, area is acontrolling parameter. Increasing area, while keeping the volumetricflow rate constant, requires that the velocity slow down. Accordingly,in order to slow the velocity, area is increased. The result of a changein velocity is to permit more time for comparatively larger droplets todrift out of their entraining airflow toward any adjacent wall, baffle,or the like.

Meanwhile, it is principally air that changes velocity. Comparativelylarger particles injected into a drift chamber will typically driftright across it to the nearest and most direct striking surface tocoalesce there. Thus, the drift chamber allows comparatively largerparticles to drift quickly to a coalescing wall or surface. The slowerair and those finest droplets entrained (those within the range ofpermanently drifting droplets), as well as some within an order ofmagnitude, slow down with the air and continue to flow through with theair toward the discharge port.

In certain preferred embodiments, a drift chamber exists immediatelybeyond the exit channel from the vapor space of the reservoir.Thereafter, the flow enters a separator. The separator may be thought ofin some respects as a drift chamber. However, its purpose is quitedifferent in certain presently contemplated embodiments.

For example, a micro cyclone is not actually a cyclone separator. Eachoperates on similar principles and acts as a separator. Here, in onepresently contemplated embodiment, the actual micro cyclone separatordoes not slow the flow down, but maintains its speed at a comparativelyhigh rate.

Air changes direction continuously about a circular pattern. Thecircular pattern is actually disposed on a spiral in which at one end ofthe spiral is an inlet and at the opposite is an outlet. Between them,the cross sectional area of the flow does not actually changesignificantly. However, the comparatively longer path provided aroundthe micro cyclone provides centripetal forces forcing the comparativelylarger droplets or particles toward the outside boundary of the microcyclone. Acting as a centrifuge it throws those comparatively largerdroplets out of the flow and against a coalescing surface in the microcyclone.

Following the micro cyclone, operating as a separator, the flow of vaporor gas and entrained droplets passes through yet another drift chamber.It has been found that having three separate drift chambers is highlyeffective. Fluid velocities are intentionally slowed. The transitingflow slowing multiple times with multiple drift chambers provides theopportunity in each instance for the comparatively larger particles tostrike a coalescing surface. Separation due to slowing and due to adirection change has been found very effective.

The addition of a separator, particularly the micro cyclone separator,has been found extremely effective to remove the comparatively largeparticles. Finally, the provision of contact coalescence bycomparatively larger particles passing through the vapor space and intothe surface of the standing liquid has also proven very effective.

Accordingly, it has been found that diffuser systems or diffusion systemin accordance with the invention, operating with the structures andfluid mechanisms in accordance with the invention, provide threevaluable benefits not found in prior art systems. First, comparativelylarger droplets do not exit the discharge port and drift down uponsurrounding surfaces. Second, this effectively diffuses and controls theamount of the essential oil diffused in order to provide a specificlevel of scent that is pleasant and effectively strong, without beingoverly strong.

Third, oil use required for a level of scent within a treated space hasbeen shown to be much more efficient. That is, usage rates of less thanhalf to a third of conventional systems result. Sometimes less thanabout one eighth to one tenth of conventional usage has resulted insystems in accordance with the invention.

In summary, the treated space has the properly controlled amount of theessential oil to provide the aroma and ambiance desired. Compared toprior art systems, whose rate of use is much greater, the essential oilsare more efficiently used. Furniture and other surfaces are not damaged,sticky, or unsightly from comparatively larger particles drifting downonto them.

In various embodiments, an integrated system may be placed within ahousing. It has been found that a reservoir may be fitted into oneportion of the housing along with the multiple drift chambers andseparators, all with the eductor nested within the same envelope (e.g.,outermost dimensions of occupied space of the device). All are fittedneatly within typically about one half of the housing.

Meanwhile, pumps, batteries, power supplies, or the like have beenfitted into the other side of the housing. This results in pleasantpossibilities for design, along with compactness, uniformity, andconvenience of integration.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing features of the present invention will become more fullyapparent from the following description and appended claims, taken inconjunction with the accompanying drawings. Understanding that thesedrawings depict only typical embodiments of the invention and are,therefore, not to be considered limiting of its scope, the inventionwill be described with additional specificity and detail through use ofthe accompanying drawings in which:

FIG. 1 is a side, elevation, cross-sectional view of one embodiment of acoaxial, triple-separation, diffusion apparatus and method in accordancewith the invention, illustrating a portion of a reservoir, containedessential oil, eductor, exit channel, micro cyclone separator, and driftchambers or separation chambers;

FIG. 2 is a perspective, partially exploded view of one embodiment of areservoir, illustrating various sizes thereof, and specificallyillustrating details of a micro cyclone separator intended to be placedwithin the flow path;

FIG. 3 is a schematic block diagram representing the side elevation viewof one embodiment of a system in accordance with the invention,illustrating the directional and functional relationships between areservoir, an eductor, the educted plume, a driving pump, and variousdrift chambers along with a distinct separator in accordance with theinvention; and

FIG. 4 is a perspective view of one embodiment of a system in accordancewith the invention in a suitable housing, with various alternativeshapes of that housing illustrated at the end of broken lines connectedto one central embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

It will be readily understood that the components of the presentinvention, as generally described and illustrated in the drawingsherein, could be arranged and designed in a wide variety of differentconfigurations. Thus, the following more detailed description of theembodiments of the system and method of the present invention, asrepresented in the drawings, is not intended to limit the scope of theinvention, as claimed, but is merely representative of variousembodiments of the invention. The illustrated embodiments of theinvention will be best understood by reference to the drawings, whereinlike parts are designated by like numerals throughout.

Referring to FIG. 1, an apparatus 10 or system 10 may include a housing12, large or small. In fact, in the illustrated embodiment, the housing12 may actually be configured as little more than a cap 12 secured toconnect certain components to a pump 14 or a pump portion 14 of thesystem 10. In fact, in certain embodiments, the pump 14 may be remotefrom the housing 12. In other embodiments, the pump 14 is located withinthe housing 12.

Referring to FIG. 1, while continuing to refer generally to FIGS. 1through 4, an atomizer 16 or eductor 16 draws from a reservoir 18, suchas a bottle, large or small, typically of a conventional size in whichsuch liquids 20 or essential oils 20 are commercially available.

In the illustrated embodiment, an exit fitting 22 or fitting 22 acts asa terminus 22 for introducing micro-atomized droplets of the essentialoil 20 into a surrounding atmosphere or environment. Typically,atomization processes do not literally “atomize.” Fluids are notsubdivided down to an atomic level. Nevertheless, the conventionalterminology of atomization refers to breaking apart a continuous supply,reservoir, or flow of a liquid 20 into airborne droplets.

However, atomization provides a distribution, typically a Gaussiandistribution of droplets exiting from any atomization system. It hasbeen found by the inventor that typical atomization systems are whollyinadequate for working with essential oils. First, essential oils tendto be solvents for service finishes on furniture. Essential oils may bereactive with plastics, other polymers, and the like. Moreover,essential oils may embed into fibers in carpets, rugs, and fabrics andevaporate, thus staining fabrics and other materials.

In the system 10 in accordance with the invention, it is desired todischarge from an exit port 23 exiting the exit fitting 22 only thosedroplets that are “comparatively smaller” as defined herein. Asdiscussed hereinabove, comparatively larger droplets are consideredthose that will drift out of a surrounding air environment sufficientlyfast. They have sufficiently high diameters to leave an oil residuebehind out of the essential oil 20 discharged.

Comparatively smaller droplets are those smaller than the comparativelylarger droplets. The idealized exit droplets are those that have theability to remain in aerosol suspension for longer than theenvironmental ventilation requires to sweep them out with ventilatingair. This is typically a period of time of about one hour. However, incertain embodiments, an apparatus 10 in accordance with the inventionmay typically discharge droplets (finest droplets) that are so smallthat they will remain indefinitely in a surrounding airflow. This isbecause the droplets have been subdivided or comminuted to a sizesufficiently small. They have such a high fluid drag in moving throughair, that the fluid drag forces of dropping with the force of gravityovercome the force of gravity, and thus maintain the micro-atomized(finest) droplets in the air basically indefinitely.

Thus, comparatively larger droplets are those that will drift out withinthe vicinity of an apparatus 10 leaving liquids on surrounding surfaceswithin a period of minutes to less than an hour. In contrast, thecomparatively smaller droplets are those that will not drop out of airin a room. They stay airborne typically for at least an hour or the timedictated by the ventilation air exchange, for example, in a room.

The micro-atomized droplets are those droplets that will not drift outof air, but remain ineffectively indefinitely. Comparatively smalldroplets are smaller than the comparatively larger droplets. It is oneobjective and benefit of an apparatus 10 in accordance with theinvention to produce a high fraction of micro-atomized droplets, and tosubstantially eliminate any comparatively larger droplets from exitingout the exit port 23 of the apparatus 10. This defines at least threesize ranges, substantially distinct.

A liquid surface 24 lying at the top of a reservoir 18 of an essentialoil 20 divides the liquid essential oil 20 from overlying air. A tube 26or siphon 26 extends down below the surface 24 of the liquid 20 to drawtherefrom.

By eduction, the tube 26 siphons or draws the liquid 20 up the tube 26or siphon 26, and into a well 28. The well 28 actually may dischargeinto a vapor space 30 operating as a first drift chamber 30. That is,the vapor space 30 is filled with air, some vapor, according to Dalton'slaw of partial pressures of vapors. The space 30 contains vaporsresulting from the evaporation to vapor of a certain portion of theliquid 20. It also contains droplets that have been educted into thatvapor space 30 or drift chamber 30.

Eduction is accomplished by the eductor 16, beginning with a nozzle 32,which may be thought of as an air nozzle 32 creating a jet of air. Thejet 33 may be thought of as a thin flow of air at a comparatively highvelocity being injected by the nozzle 32 or air nozzle 32 toward thevapor space 30. The vapor space 30 is typically substantially quiescentwith respect to the comparatively higher velocity of the jet 33emanating from the air nozzle 32.

The nozzle 32 is driven or fed by a line 34 bringing air from the pump14. The line 34 may be represented by a path 34 through multiplecomponents, such as solid tubes, flexible tubes, hoses, pipes, or thelike. All of these may contribute to or become a portion of the line 34connecting a pump 14 to an air nozzle 32.

An eductor nozzle 36 is not required in every eductor 16, but provides asignificant benefit. For example, systems much larger than a diffuserapparatus 10 in accordance with the invention may use the principle ofeduction. In fact, eduction may be used to move large bodies of fluid inindustrial plants. Eduction may be used to effectively pumpcomparatively larger conduits of fluid by injection of small,comparatively higher velocity jets of a cleaner fluid more adapted to bepumped.

Thus, here, the eductor nozzle 36 provides a certain amount ofcontainment of the jet 33, and of the surrounding liquid 20 drawn intothe well 28. Eduction happens by the jet 33 from the nozzle 32 passingoutward through the liquid 20 in the well 28. The jet 33 therebyentrains from the surrounding surface of that liquid 20, dropletsstripped off by the turbulent airflow at the boundary of the liquid 20passed by the jet 33.

One property of jets 33, from a fluid engineering point of view, is thata jet 33 is a flow of one fluid of higher momentum through a surroundingenvironment of a fluid of different momentum, which may be the same ordifferent type of fluid. Thus, one may have a jet of hot water risingthrough a surrounding environment of colder water. Jets may be air inwater or water in air. One may have a jet of high speed water impingingon a reservoir of quiescent or slower flowing water.

Here, the jet 33 constituted by air coming from the nozzle 32 passes outthrough the eductor nozzle 36, into the vapor space 30. It draws with itentrained quantities of the liquid 20, thereby blasting into many manydroplets what was originally a continuous, contiguous liquid. Thus, theeductor nozzle 36 introduces the jet 33 containing both air andentrained droplets of oil 20 into the vapor space 30. The vapor space 30operates as the first drift chamber 30 in a separation process.

The flow 37 of air and entrained droplets passes out from the vaporspace 30 or drift chamber 30. Any amount of the liquid droplets 39 thatstrike a wall, drift downward out of entrainment with the air, or thelike will either shatter, coalesce, or both. Coalesced oil will passback through a drain 38 into the reservoir 18, and the liquid 20contained therein. However, what remains in the flow 37 will exit thevapor chamber 30 toward another drift chamber 40 by way of a connectingchannel 42.

A characteristic of each drift chamber 30, 40, and any interconnectingchannels 42 is that each channel 42 constricts the flow by changingdownward (reducing) the available cross sectional area of flow. Thus,each channel 42 effectively accelerates, or requires the flow 37 toaccelerate to a higher speed in order to maintain a substantiallyconstant flow of air through the entire pathway of the apparatus 10.

In the illustrated embodiment, the channel 42 has a much smaller crosssectional area than does the drift chamber 40, and a smaller crosssectional area than does the drift chamber 40. With each acceleration offlow through a channel 42, two benefits are obtained. First, pressure(static pressure, as that term is used in fluid engineering) reduces.Meanwhile, velocity increases. Then, each channel 42 typically casts itsflow 37 into a subsequent drift chamber 40 where the flow 37 must slowand change direction.

The comparatively larger droplets tend to continue in the direction oftheir initial momentum through the channel. They often crash into orsmash into an obstructing barrier, such as an adjacent wall, baffle, orthe like. This causes the droplets 39 that strike solid surfaces toshatter, coalesce, or both at those surfaces. Surfaces collect oil andflow it back through the drain 38 to arrive back in the liquid 20collected in the reservoir 18.

This provides the benefit of not only reducing the discharge ofcomparatively large droplets, substantially to zero in the experience ofthe system 10, but permitting the discharge from the exit port 23 ofonly comparatively smaller droplets. Restricting the discharge flowlimits soil output to micro-atomized droplets that will driftsufficiently long, or even indefinitely, in surrounding air.

A separator 44 as used herein means a specific type of separatorseparate from a drift chamber 30, 40, 50. A drift chamber relies on atleast one change of direction, surrounding walls to smash, subdivide, orcollect comparatively larger droplets 39, and so forth. In that context,every drift chamber 30, 40, 50 is a separator 44 of sorts.

However, the separator 44 is specifically a low-aerodynamic-lossseparator. Baffles lose energy and driving pressure. Abrupt obstructionall do. One such unique separator is designated as a micro cycloneseparator 44. A micro cyclone 44, a coined term, is not actually acyclone. Cyclone separators are used in certain industrial processes.Cyclone separators literally set up a vortex in a two-phase system. Thetwo phases may be solid and liquid, solid and vapor (e.g., air, gas),vapor and liquid, and so forth.

Here, a micro cyclone 44 uses continual or sustained centripetal forceas a separation mechanism. However, it does not permit an actual vortex,as that mechanism has shown to be ineffective in essential oil atomizersystems 10 such as a system 10 in accordance with the invention. It hasbeen found that sufficiently high speeds with turbulent flow (terms ofart in the fluid engineering technology, which may be understood byrepair to any textbook on the subject) have a tendency to re-entraincomparatively larger droplets. This can be problematic.

It is desired in a system 10 and method in accordance with the inventionto remove the comparatively larger droplets permanently, and not simplyrecycle them, re-entrain them, reaccelerate them, and re-smash them intoobstructions. Rather, it is considered more effective to simply separatethem out, coalesce them, and return them back to the liquid 20 in thereservoir 18. Thus, cyclone separators of conventional types do notpermit the proper separation processes. In fact, one reason for thedrain 38, is to provide an alternative path for liquid 20 draining backinto the reservoir 18. It has been found more effective to remove largerdroplets from downstream processes rather than accelerating andcomminuting them, or risking re-entrainment by countercurrent flowbetween the returning liquid 18, and out going flow 37 of droplets 39.To permit significant counter flow throughout would invite turbulentstripping of droplets off the surface of liquid, thus reintroducingcomparatively large droplets.

To be sure, the micro cyclone 44 does permit counter flow. However, dueto the almost full circle, the micro cyclone 44 tends to throw droplets39 radially outward against an outer wall. It may actually include acircumference path longer than a full circle. Liquid coalesces anddrains back out of the spiral shape of the micro cyclone 44, eventuallyworking its way back out through the drain 38 and into the reservoir 18.

The separator 44 is discussed in considerable detail in the patentapplications incorporated herein by reference and identifiedhereinabove. It is sufficient to point out that the micro cycloneseparator 44 illustrated provides a cleverly constructed device 44having a top half 45 a and bottom half 45 b defining an entrance 46 andexit 48 of substantially the same cross sectional area. The conduit 52therebetween traverses a spiral beginning at the entrance 46 receivingthe flow 37 from the drift chamber 40, and transferring that flow abouta centrifugally separating path about the circumference of a circle,discharging the flow 37 at the exit 48 into the drift chamber 50.

Here, the cross sectional area available for traverse or passage of theflow 37 through the drift chamber 40 is extremely large compared to thecomparatively smaller cross section of the entrance 46 and exit 48 ofthe micro cyclone separator 44. Thus, once again, the separator 44 ormicro cyclone 44, in this instance, operates as a conduit 52 or channel52 requiring acceleration of the velocity of the flow 37. It dischargesinto a drift chamber 50 where that flow 37 will again be slowed topermit time for drifting. The flow 37 will change direction, providinganother opportunity for any oversized droplets, or any other droplets39, to strike walls.

It is important to understand that micro-atomized droplets 39 do nottypically strike any surrounding solid surfaces. Of course, boundarylayer theory is well documented in any text on the subject, and even inmost texts directed to basic fluid mechanics. Such will explain how athin boundary layer near any solid surface does tend to extend from astationary fluid at the solid surface out to a free stream velocity inthe principal flow passing thereby.

Nevertheless, the nature of micro-atomized droplets 39 makes them sosmall that they accelerate as the entraining air accelerates, anddecelerate with the air when it slows due to the overwhelming dominanceof fluid drag. This is directly in opposition to the behavior of thecomparatively larger droplets 39. The comparatively larger droplets 39instead have such momentum, that their drag forces (body drag or fluiddynamic drag as understood in the art of engineering fluid mechanics)are oppositely disposed. Drag forces on the comparatively largerdroplets are not as comparatively large, in comparison with thegravitational forces and momentum forces. The comparatively largerdroplets, once accelerated, do not readily change direction. They aretypically smashed into walls in response to any abrupt change ofdirection. They tend to strike, comminute to smaller sized droplets,coalesce, or some combination thereof.

It has been found that a micro cyclone 44 in accordance with theinvention is a very effective separator 44. It provides a comparativelylong path (pi or arc of angle times the diameter of the circle thatdefines the conduit 52) or approximately that distance, all the whilesubjecting the flow 37 to a tight turn radius. By continuing for asufficiently long time and path length, it permits comparatively largerdroplets to drift under centripetal force outward to be coalesced,collected, and drained back into the reservoir 18.

The drift chamber 50 may be larger, smaller, or comparatively equal insize, path length, change of direction, change of cross sectional area,or the like with respect to the other drift chambers 30, 40. However,there is not a requirement that any drift chamber 30, 40, 50 be an exactsize. The basic components are cross sectional flow area, a distance oftravel permitting time for settling out a comparatively larger droplets,a change of direction (often both in and out), and an obstruction suchas a wall, baffle, or the like. These capture comparatively largerdroplets 39 that cannot make the changes of direction required by theflow 37 passing therethrough.

Meanwhile, the channel 54 requires a change in direction and velocity inorder for the flow 37 to eventually find its way therethrough. Just aswith the lower drift chamber 40, a channel 54 provides a path for theentraining air and droplets 39 of the flow 37. The drift chamber 60 alsopresents additional changes of direction, changes of cross section, andso forth. Likewise, the drift chamber 60 typically provides a drain 56for return of fluids back “upstream” with respect to the direction ofthe flow 37 from the eductor 16 toward the exit port 23.

In certain embodiments, channels 42, 52, 54 may be provided with fences58 or borders 58. Several different borders 58 are illustrated asexamples 58 a, 58 b, 58 c. A reference number represents a generic item,and the trailing reference letter identifies a specific instance whenthat is needed. A border 58 assists in maintaining separation.

For example, a border 58 or fence 58 may be placed to directaccumulated, coalesced liquid 20 away from channels 42, 52, 54. Oil isurged to return back through the drains 56, 38 to consolidate with theliquid 20 in the reservoir 18.

However, in order to further minimize stripping of additionalcomparatively large droplets from the surface of such returning liquids20, drains 38, 56 may be separated horizontally from the channels 42,52, 54. These drains may be sized smaller to encourage the flow 37 topass through the channels 42, 52, 54, to the exclusion of the drains 38,56.

Also, the fences 58 operate to reduce the tendency of returning liquidto drain down around the boundaries or edges of the channels 42, 54.This reduces the tendency for comparatively higher speed flows throughthe channels 42, 54 to be exposed to the liquids, and to engage inturbulence and entrainment of droplets stripped from the surface of thereturning liquid 20.

Referring to FIG. 2, while continuing to refer generally to FIGS. 1through 4, the principles of operation have been described for thisembodiment of a system in accordance with the invention. Various driftchambers 30, 40, 60 may be built into the housing 12, the exit fitting22, and so forth. Such embodiments as those illustrated in FIG. 1 arenot shown in internal views in this illustrated embodiment. However,details of the micro cyclone 44 are illustrated, including, clockwisefrom the top, a top plan view, a front elevation view, a bottom planview, and a rear elevation view. Meanwhile, an exploded view of the twohalves 45 a, 45 b of the micro cyclone 44 is illustrated in the centerof the other views.

Of course, various sizes of reservoirs 18 a, 18 b, 18 c, 18 d may beconfigured to fit within or outside of the housing 12. In certainembodiments, the reservoir 18 may be provided with some type of anadapter 64 that operates much as a cap 65 that would otherwise seal thereservoir 18. Here, an adapter 64 may be provided with threads 66 oranother fitting 66 connecting to the housing 12 or other constituentsrequired to connect to the upper drift chambers 40, 50, 60.

Referring to FIG. 3, while continuing to refer generally to FIGS. 1through 4, a schematic diagram illustrates a system 10 in accordancewith the invention in one embodiment. It has been found that a plume 70is generated by the eductor 16. That is, for example, the jet 32entraining droplets 39 of the liquid 20 in the stream of air from thepump 14 and line 34 continues to exchange momentum with the surroundingenvironment in the vapor space 30 or first drift chamber 30.

Plumes 70 are defined in the engineering art of fluid mechanics. One mayrepair to papers, textbooks, and treatises on the subject. A plume iseffectively an expanding jet. A jet typically is modeled or representedas momentum injected into a surrounding environment. The jet begins toexchange momentum with the surrounding fluid, thereby creating a plume.The momentum originally embodied in the jet is exchanged withsurrounding material, with some losses. Flowing that increasing amountof material forward in an ever-widening plume 70 reduces maximumvelocity. That is, continuing to exchange momentum and pick up massflow, results in slowing the maximum, central flow velocity. Totalmomentum cannot increase with widening the extent of the plume 70.

This plume 70 operates with the surface 24 of the liquid 20 as a capturedevice. Rather than smashing against a wall and coalescing with otherdroplets so disposed, the plume 70 discharges directly into the surface24 of the liquid 20. The flow 37 is opposite and flow parallel to theexit flow 37. This abrupt and complete reversal of flow direction,immediately coalesces a certain fraction of the comparatively largerdroplets 39 with the bulk of the liquid 20 in the reservoir 18.

Thereafter, only oil 20 in the flow 37 that has navigated the abruptchange of direction is still remained entrained in the air. It exits inthe flow 37 through the channel 42 arriving at the drift chamber 40.

The flow 72 of air through the eductor 16 results in a flow 74 that hasa somewhat variable constitution. Therefore, even though we discuss theflow 37 generically through the system 10, the constitution of the flow72 is air. The constitution of the plume 70 is air entraining droplets39 along a typical (e.g., Gaussian) distribution of droplets 39. ThisGaussian distribution is truncated or filtered, so to speak, byentrapment of the comparatively larger droplets 39 in the liquid 20.Thus, the flow 74 has a different and changing constitution, as does theflow 37. Although constituting about the same amount of air, it does notconstitute the same number nor the same size distribution of droplets39.

Following the drift chamber 40, the flow 37, 76 has again been strippedof its comparatively larger constituents. Meanwhile, the separator 44conducts its centripital operation, as described hereinabove. Thus, theflow 37, 78 reaching the final drift chamber 60 is further separated toinclude only the comparatively smaller droplets 39 in the flow 37.

One will note that the schematic illustration includes only three driftchambers. In contrast, the previous description included four. It hasbeen found that a system 10 in accordance with the invention operatessubstantially better with three drift chambers than with two. With threedrift chambers 30, 40, 50, 60 rather than two. Also, it has been foundthat a micro cyclone separator 44 between two of the drift chambers,such as drift chamber 40 and drift chamber 60 illustrated here tends togreatly improve the overall efficacy. Thus fluid pressure losses arereduced with three drift chambers removing the comparatively largerdroplets. Three drift chambers 30, 40, 50, 60 where one uses contactremoval, with a microcyclone separator provides excellent separationwith acceptable pressure drop along the flow path. This results inrestricting the flow 37 to contain only the comparatively small and themicro-atomized droplets 39.

Ultimately, the flow 80 discharged from the outlet port 23 preferablycontains only micro-atomized droplets 39. As a practical matter, it hasbeen observed that a system 10 in accordance with the invention, havingthe collinear or parallel but oppositely directed flows 33 and 37 withinthe vapor space 30 of the reservoir 18 is very effective as a firstseparation process. Meanwhile, having at least two other drift chambers40, 50, 60, with a micro cyclone separator 44 between two of them hasproven extremely effective. This reduces the use of essential oils 20with no effective loss in aroma intensity in the space serviced by adiffuser 10 or system 10.

Thus, the effectiveness, the actual evaporation and sustained driftingof comparatively small and micro-atomized (finest) droplets 39 isachieved. This occurs without the loss of liquid represented by thetemporarily drifting, comparatively larger particles that do not remainsustained in the air over comparatively long (e.g., air exchange times,often about an hour or more) in the air environment being treated by thediffuser 10.

Referring to FIG. 4, while continuing to refer generally to FIGS. 1through 4, various embodiments of housings 12 are illustrated, havingspace for a pump 14 integrated into the housing 12 with the driftchamber 30, 40, 50, 60 and the micro cyclone separator 44. Designsinclude various shapes, and various connection schemes operating intandem, side by side, in various geometries, and even stacked axially.Various types of exit fittings 22 may be used, including thoseillustrated, and others.

Fluid communication between a pump 14 through a line 34 is necessary toprovide a turbulent stream or jet 36 of air entraining droplets drawnfrom the liquid 20 and the reservoir 18, as described hereinabove.Nevertheless, integrated packaging provides a simple system in whichsuch supporting structures as a pump 14, lines 34, and even the internaldetails of the drift chambers 30, 40, 50, 60, and so forth are neatlyhidden from view, while operating effectively.

The present invention may be embodied in other specific forms withoutdeparting from its purposes, functions, structures, or operationalcharacteristics. The described embodiments are to be considered in allrespects only as illustrative, and not restrictive. The scope of theinvention is, therefore, indicated by the appended claims, rather thanby the foregoing description. All changes which come within the meaningand range of equivalency of the claims are to be embraced within theirscope.

What is claimed and desired to be secured by United States LettersPatent is:
 1. A method of diffusing a liquid into an environment, themethod comprising: providing a reservoir shaped to contain the liquidbetween a wall of the reservoir and a surface of the liquid therewithin;providing an atomizer operably connected to receive a flow of air, and,in response thereto, draw a portion of the liquid from the reservoir andentrain the portion into the flow as droplets directed at the surface;separating, by the surface, comparatively smaller droplets, remainingwith the flow, from comparatively larger droplets striking andcoalescing with the surface; and further segregating the comparativelysmaller droplets by passing the flow through a drift chamber effecting areduction in velocity of the droplets in the flow.
 2. The method ofclaim 1, wherein the atomizer comprises a nozzle and the methodcomprises orienting the nozzle to inject the flow vertically downwardtoward the upper surface.
 3. The method of claim 1, comprising atomizingthe portion into the droplets by exchanging momentum directly betweenthe flow and the portion.
 4. The method of claim 1, wherein the atomizercomprises a first nozzle providing the flow as a jet of air and a secondnozzle feeding the portion into the jet.
 5. The method of claim 4,wherein the atomizer comprises a third nozzle injecting the jetcontaining the droplets into the first chamber.
 6. The method of claim1, comprising providing a vapor space in the reservoir, above thesurface and passing the flow through the vapor space toward the surface,followed by passing the flow through the vapor space away from thesurface.
 7. The method of claim 1, comprising providing a vapor spacewherein separating comprises segregating the droplets by reversingdirection of the flow to move away from the surface and through thevapor space to exit the reservoir.
 8. The method of claim 1, comprisingproviding at least one drift chamber wherein a cross sectional areaoccupied by the flow is substantially greater within the drift chamberthan upon entry thereto and upon exit therefrom, reducing a flowvelocity of the droplets in the drift chamber, to promote separation ofdroplets by gravity, and then accelerating the flow velocity during exittherefrom.
 9. The method of claim 8, comprising providing at least twodrift chambers downstream from the atomizer.
 10. The method of claim 9,comprising providing at least three drift chambers, wherein a vaporspace in the reservoir above the surface operates as one of the at leastthree vapor spaces.
 11. An apparatus comprising: a reservoir structuredto contain a liquid defining a surface, the reservoir operably connectedto feed a portion of the liquid from the reservoir to a nozzle inresponse to a flow of air; a pump providing the flow of air; the nozzleshaped and oriented to introduce downward, toward the surface, the flowcontaining the portion, atomized into droplets of the liquid; thereservoir structured to provide a vapor space above the surface andoperable to slow a velocity of the flow therethrough and reverse itsdirection, separating out from the flow comparatively larger ones of thedroplets unable to remain with the flow passing upward away from thesurface and out of an exit from the vapor space.
 12. The apparatus ofclaim 11, wherein the vapor space operates as a drift chamber, whereinan inlet for the flow and an outlet for the flow each have a smallercross sectional area than an area available to the flow passingtherebetween.
 13. The apparatus of claim 12, comprising a second driftchamber above the vapor space, having an inlet and an outlet, eachsmaller in cross-sectional area than a cross-sectional area of the flowtherebetween in the second drift chamber.
 14. The apparatus of claim 13,comprising a third drift chamber and a wall across the outlet of thesecond drift chamber blocking direct connection between the second andthird drift chambers, the wall traversed by a channel making acircuitous path through the wall to separate out by centripetal forceadditional droplets.
 15. The apparatus of claim 11, comprising a driftchamber, a wall between the drift chamber and the vapor space blockingdirection connection therebetween, and a channel passing axially andcircumferentially through the wall from the vapor space to the driftchamber.
 16. The apparatus of claim 11, wherein the nozzle is configuredas an eductor discharging axially into the vapor space, normal to thesurface.
 17. The apparatus of claim 11, comprising a drift chamber and aseparator above the vapor space connected by a return channel to returndroplets coalesced thereby into the reservoir.
 18. An apparatuscomprising: a reservoir defining an axial direction and circumferentialdirection, and shaped to contain a liquid defining a surface thereof anda vapor space in the reservoir above the surface; an injector operablyconnected to inject directly downward toward the surface a jet of air asa flow to entrain, as droplets therein, the liquid drawn from thereservoir in response to the flow; a separator comprising at least oneof the vapor space, the surface, a drift chamber above the reservoir,and a channel passing axially and circumferentially, simultaneously,through a wall obstructing the flow downstream from the injector. 19.The apparatus of claim 18, comprising: the separator operating by atleast one of centripetal force, surface tension, and collision to urgecoalescing of the comparatively large droplets before flowing back intothe reservoir.
 20. The apparatus of claim 19, comprising providing atleast one drift chamber wherein a cross sectional area occupied by theflow is substantially greater within the drift chamber than at entrythereto and at exit therefrom, reducing a flow velocity of the dropletsin the drift chamber, to promote separation of droplets by gravity.